Documentation

Validation rules

Every issue in a CueNorm report names one of these rules. Each page explains what is checked, how it is measured and how to fix it.

Always checked

• NON_POSITIVE_DURATION Reports a subtitle whose end time is not after its start time.
• SUBTITLES_OUT_OF_ORDER Reports a subtitle that starts before the previous one: the file is not in chronological order.
• SUBTITLE_OVERLAP Reports a subtitle that starts while an earlier one is still on screen in the same display area.
• SOURCE_LANGUAGE_MISMATCH Warns when the subtitles are in another language than the one the profile expects.
• FILE_FORMAT_MISMATCH Refuses a file whose content is in another format than its extension says.
• NO_SUBTITLES_READ Refuses a file in which no subtitle could be read.
• FILE_READING Lists what CueNorm reports while reading a file, before any profile rule: format errors, skipped cues and features it cannot keep.
• CONVERSION Lists what CueNorm reports while converting a file: the transformations it applied, and what the destination format could not hold.

Text layout

• MAX_CHARACTERS_PER_LINE Limits the number of visible characters on each line of a subtitle.
• MAX_LINES Limits the number of lines a single subtitle may display.
• FORBIDDEN_STYLE Forbids a text style that the destination does not accept.
• FORBIDDEN_CHARACTERS Forbids characters that the destination does not accept in subtitle text.

Reading speed

• RECOMMENDED_READING_SPEED Flags subtitles above the recommended reading speed that still stay within the hard maximum.
• MAX_READING_SPEED Rejects subtitles that must be read faster than the profile's maximum reading speed.
• MIN_READING_TIME Checks that each subtitle stays on screen long enough to be read, using a table of characters and durations.

Timing

• MINIMUM_DURATION Requires each subtitle to stay on screen for at least a minimum time.
• MAXIMUM_DURATION Limits how long a single subtitle may stay on screen.
• MINIMUM_GAP Requires a minimum pause between the end of a subtitle and the start of the next one.

Teletext

• MAX_TELETEXT_CELLS_PER_ROW Limits the width of each teletext row of an EBU-STL file, measured in display cells.
• MAX_TTI_BLOCKS_PER_SUBTITLE Reports EBU-STL subtitles whose text does not fit in a single TTI block.
• STL_HEADER_VALUES Requires the technical fields of an EBU-STL header to hold the values the destination imposes, such as the code page or the teletext level.

SDH

• SDH_COLOR_CONVENTION Checks that every text color of a subtitle for the deaf and hard of hearing (SDH) belongs to the color code of the destination.

Other

• SDH_NO_COLOR Warns when a file delivered as subtitles for the deaf and hard of hearing (SDH) uses no color at all.
• ALLOWED_TEXT_COLORS Accepts only the text colors of the destination's palette.
• ALLOWED_CHARACTERS Accepts only the characters of the destination's character set.
• REQUIRED_METADATA Requires programme metadata that the destination wants in the delivered file, such as the programme title or the on-air reference.